Persisting intrahospital transmission of multidrug-resistant Klebsiella pneumoniae and challenges for infection control

An Outbreak of Carbapenem-Resistant Klebsiella pneumoniae of K57 Capsular Serotype in an Emergency Intensive Care Unit of a Teaching Hospital in China

The emergence of carbapenem-resistant hypervirulent K. pneumoniae (CR-hvKP) strains has increased the threat posed by K. pneumoniae. Here, we described an outbreak of 32 CR-hvKP isolates from the emergency intensive care unit (EICU) of a teaching hospital in China. Thirty-two CRKp isolates were collected from six patients and their surrounding environment in EICU. Antimicrobial susceptibility testing was performed using VITEK 2 compact system, E-test or the broth microdilution method. All isolates were serotyped, antimicrobial resistance genes and virulence-associated genes were screened using PCR. Multilocus sequence typing (MLST) and pulse-field gel electrophoresis (PFGE) were employed to characterize the genetic relationships among the CPKP isolates. The virulence capability of 11 CRKp isolates from six patients was evaluated through Galleria mellonella larva infection assay. PFGE showed that all 32 isolates belonged to one cluster, and MLST revealed that belonged to ST11. All isolates exhibited high resistance to β-lactam antibiotics, quinolones, and aminoglycosides. They were susceptible to ceftazidime/averbatan, tigecycline, and colistin. All 32 isolates harbored bla_KPC−2, bla_SHV−11, bla_TEM−1, rmtB, and qnrD. The serotype of all 32 isolates was K57. All 32 isolates contained 6 virulence genes, namely, fimH, iucB, mrkD, rmpA, uge, and wabG. Infection assays demonstrated high mortality in the Galleria mellonella model. Following measures implemented by the hospital, the outbreak was controlled. The mortality rate was 50.0%. The epidemiology of CR-hvKP should be monitored closely to detect early indications of this emerging public health threat.

Identification of a Cluster of Extended-spectrum Beta-Lactamase-Producing Klebsiella pneumoniae Sequence Type 101 Isolated From Food and Humans

We report a cluster of extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae sequence type 101, derived from 1 poultry and 2 clinical samples collected within the setting of a prospective study designed to determine the diversity and migration of ESBL-producing Enterobacterales between humans, foodstuffs, and wastewater.

Validation and Extrapolation of a Multimodal Infection Prevention and Control Intervention on Carbapenem-Resistant Klebsiella pneumoniae in an Epidemic Region: A Historical Control Quasi-Experimental Study

Objective: To verify the effects of comprehensive infection prevention and control (IPC) interventions for the prevention of the cross-transmission of carbapenem-resistant Klebsiella pneumoniae (CRKP) within intensive care units (ICUs) in an epidemic region.

Methods: A historical control, quasi-experimental design was performed. The study was conducted between January 2017 and December 2019, following the implementation of a multimodal IPC bundle. The baseline period was established from January 2013 to June 2013, when only basic IPC measures were applied.

Results: A total of 748 patients were enrolled during the entire study. The incidence of ICU-acquired CRKP colonization/infection was 1.16 per 1,000 patient-days during the intervention period, compared with 10.19 per 1,000 patient-days during the baseline period (p = 0.002). The slope of the monthly incidence of CRKP at admission showed an increasing trend (p = 0.03). The incidence of ICU-acquired catheter-related bloodstream infections caused by CRKP decreased from 2.54 to 0.96 per 1,000 central-line-days (p = 0.08). Compliance with contact precautions and terminal room disinfection improved during the intervention period. All environmental surface culture samples acquired after terminal room disinfection were negative for CRKP.

Conclusion: Our findings suggest that in epidemic settings, multimodal IPC intervention strategies and consistent monitoring of compliance, may limit the spread of CRKP in ICUs.

Molecular Characteristics of Carbapenem-Resistant Klebsiella pneumoniae Isolates Producing blaVIM, blaNDM, and blaIMP in Clinical Centers in Isfahan, Iran

Background: The emergence and spread of metallo-beta-lactamase (MBL)-producing Klebsiella pneumoniae are growing global public health concerns. One of the most common mechanisms of carbapenem resistance is the production of MBLs, including Verona integron-encoded metallo-beta-lactamase (VIM), New Delhi metallo-beta-lactamase (NDM) and imipenemase (IMP). Objectives: This study aimed to investigate MBLs production among K. pneumoniae isolates. Methods: In this study, 240 K. pneumoniae isolates were collected from clinical samples in three clinical centers of Isfahan, Iran, during February 2017 and November 2018. All isolates were identified using biochemical, microbiological, and molecular methods, and then antimicrobial susceptibility tests were performed to find MBL-producing isolates via phenotypic and genotypic detection methods. Moreover, the minimum inhibitory concentration (MIC) of antibiotics against MBL-positive strains was determined by E-test. Eventually, the clonal relatedness of the MBL-positive strains was analyzed using both multilocus sequence typing (MLST) and rep-PCR. Results: Overall, 33.7% (81/240) of the isolates were resistant to carbapenems, among which 25 (30.8%) were considered MBL-positive. Among 81 strains resistant to carbapenems, genes encoding FimH, rmpA, and mrkD were detected in 87.6% (71/81), 11.1% (9/81), and 67.9% (55/81) of the isolates, respectively. Besides, TEM and SHV as antibiotic resistance genes were detected in 49.3% (40/81) and 80.2% (65/81) of the isolates. But, magA was not detected in any of the tested isolates. The PCR results revealed that blaVIM-1 was the most prevalent gene (13.6%; 11/81), while both blaIMP-1 and blaNDM-1 were only detected in two isolates. Multilocus sequence typing demonstrated that 15 MBL producers belonged to three sequence types (ST): 11 to ST23, two to ST1147, and two to ST15. Finally, rep-PCR typing showed similar fingerprints with MLST, except for ST23, such that ST23 was discriminated in two clonal groups, suggesting the greater discriminatory power of rep-PCR. Conclusions: Here, we reported the emergence of MBL-producing K. pneumoniae in clinical centers of Isfahan, Iran. The findings are alarming and represent the urgent need for the application of infection control programs.